Tension control, stop mechanism, and warning signal for knitting machines



Aug. 28, 1945.

i TENTION CONTROL, sToP MECHANISM, AND

WARNINGSIGNAL FOR KNITTING MACHINES R. N. AUBLE Y 2,383,838

Filed July s, '1944 5 @v -Hq. j.

Patented-Aug.` 28, 1945 TENSION CONTROL, STOP MECHANISM, AND WARNINGSIGNAL FOR KNITTING MA @EINES Robert N. Auble, indianapolis, llml.

Application July 3, i944, Serial No. 543,248

i7 claims. (ci. .ss-'163) This invention relates to improvements intension control and stop mechanisms for knit ting machines, coningmachines and the like.

It is particularly adapted toequalize tension on yarn, thread, etc., inmachines in which the yarn is freely'fed to the machine withoutrestraint or restriction at the vsource of supply, but which encountersinthe machines variable factors of demand, such as, for example, arefound inthe carrier arms of hosiery knitting machines, which intravelling forward and backward across the needle. bars subject the yarnto a constantly varying rate of travel and consequent va-rying tension.

This invention is also particularly adapted to stop the knitting machineshould the yarn or thread be broken at any point, should it develop aknot r slub such as wouldbreak the thread in its travel through themachine, or should any factor develop a tension on the thread eithergreater or less than the predetermined limits imposed by the initialadjustment of the device. i

It is likewise particularly adapted to energize a warning signal such asto light a warning lamp or ring a warning belhand at the instant themachine is stopped by reason of a thread break, run out, orincreasedtension, etc. Such signal may be individualized to enable theoperator of the machine to locate promptly the source of trouble byindividually indicating the thread which has caused the stoppage.

Other advantages and novel features of the invention will be lset forthmore fullyv in the speciilcation. y i

The full nature of the invention will be under- .switch contactorsr 9and the tension `arm 4. Same are offset axially relative to pin 20.

In its preferred' form a single switch member I2 is employed to energizeand thus actuate an electronicrelay or the like, which in turn may lighta Warning lamp and open an electric cirthe forward (arm associated) endof pin 20,

stood from the accompanying drawing and the y following description andclaims:

In the drawing:

Fig. 1 is a. central section vof the essential parts of the device.

Fig. 2 is a perspective view of the device.

Fig. 3 is a wiring diagram of a circut and in which is included aplurality of the, devices and one `preferred arrangement of warningsignals.

Fig. 4 is a perspective view looking toward the rear of the spindlemember, contactors, counter weight and tension arm.

The frame consists of base member I6, upper eyelet supporting tongue I5,side brackets I8, and the window Il in the base. Brackets I8 carry andsupport on point bearings 6 the spindle member or spindle 8, which ispivoted on point bearing sockets 5 and moves freely in a vertical plane.through an angle of approximately 1059.

cuit to theA driving motor and its associated dy- .namic brakingmechanism of a machine such` as a knitting or coning machine. Al secondswitch blade I2a may be mounted, however on the basel member I6 andselectively contact a second pair of contactors 9a and Illa on spindlet, similar to contactors 9 and Ill, should .it be desired to separatethe warning light function from the stop motion function of theelectronic relay. The contactors 9 and II) and 9a' and Ia are eachoppositely oii'set from pin 20.

The switch blade I2 is insulatably supported by insulation plate I3 onthe base member I6. Switch blade I2a is similarly mounted on the base.Also vmounted on said base member I6 is a flat spring IB wi-th anangular end which y extends through the window I'I and normally liesabove the counterweight ,1. The end 2I of said spring I 4 is sopositioned that it is engaged by when the tension arm d approaches theupper I progressive.

In normal use thread 22 is threaded through porcelain eyelet Icarried bytongue l5, vthence through eyelet 2 on tension arm t, thence througheyelet 3 in base I6 and thence to the machine upon which the present.device is mounted. Thread movement through the eyelets is in thedirection shown by the arrows. Said movement is resisted by the frictionof eyelets I and 2 'upon the thread. The amount of frictional resistancefor a given type lof yarn is proportional to the velocity of threadmovement and to the position of the tension arm Il. Since tension arm Bis free to move in a vertical plane, which is also the plane of thestrands of yarn, eyelet 2 is lifted toward eyelet 3 as the velocityofthe movement of the thread is increased, and conversely is loweredagain toward its lower position as velocity of movement is decreased.Thus, except in the case of breaks, runouts, or slubs, the position ofthe tension arm 4 is at all times responsive to variationsin the rateoi' travel of the yarn or thread to the knitting or like machine.

1t 1s to be noted, however, that should a knot or slub develop in thesource of supplyror should the thread be broken at' any point, then theposition of the tension arm 4 is no longer responsive solely to thefriction in eyelets I and 2, but is also responsive to the undesiredchange in tension. Should such a change in tension develop at the sourceof supply, then tension arm 4 drops to its lower limit position in thecasel of too little tension, or is lifted to the upper limit position ifthe tension be too great. As the tension arm 4 approaches its upperlimit position, its pin 2li engages spring I4 at 2| in such a way thatiree movement of the said tension is impededL slightly, so that switchcontact 9 will not immediately contact switch blade I2, except as thetension is such as probably will break the thread if such tension becontinued. The foregoing also applies to contact 9a and switch I2a whensame arev used. Spring I4 is selected and adjusted to accommodate thethread which is being currently used.

The tension arm 4 and counterbalancing weight 1 are so constructed .thatthe moving member is in exact equilibrium when the tension arm 4 ispositioned in the same straight line as pin `2t which carries thecounterbalancing weight 1 at its opposite end. Adjustable control oftension is secured by bending the tension arm 4 downward, thus movingthe center of gravity of the moving system to a position below thepoints of support, in this case bgelow a horizontal line drawn throughpoint bearings 6. When the thread or yarn is moving through eyelets I, 2and 3, as hereinbefore described and in the direction of the arrows,`eyelet 2 is lifted toward eyelet 3. Thus the tension arm 4 is a leversystem operating about a center of moments at the point bearings B andarranged in such manner that the center4 of gravity oi the whole movingsystem is lifted by the tension arm 4 in its upward movement.

'I'he mechanical advantage of the said lever 'system is the ratio of thelength of the tension arm to the distance to which the center of gravitywas lowered by the bending of the tension arm downward as described.Said mechanical advanaasaese proximately parallel and of their liftingforce is their sum. But as tension arm 4 is moved upward ,the anglebetween the -two lifting forces is increased, and their treatment isreduced.'

It will be also observed that the effective lifting component of theforce is at right angles to tension arm 4', and that this said eiectivelifting component of the force is proportional to the sine of the anglethrough which the tension arm has been moved, increasing as the tensionarm approaches its upper position.

Thus the resisting force due to the lifting of y the center of gravityincreases and the eiectfile component of the lifting force increases inthe same proportionate rate so that they are at all l times in balanceagainsteach other, so that the for exemplication.

resultant edect is to produce a constant tension `onI the yarn,within'the limits predetermined by and the former to terminal 4I bynormally closed switch 41 and line 48. Terminal 42 has line 49 i Iconnected thereto and switch contact '50.

When switch 41 is closed. the motor is energized. When it is opened,said switch engages contact El! and energizes the dynamic brake in tageis therefore adjustable by the'amount of bending of the tension arm, andwhen onceltrhas been adjusted tol provide thedesired tension, no furtheradjustment is necesssary. Bending is not the only method of adjustment,but appears to be the easiest.

'In the adjustment which has been described it will be observed that asthe tension arm 4 is lifted towardv eyelet 3, the center of gravity mustbe lifted, and since the moment of force exerted by said center ofgravity is proportional to the sine of the angle' of the movement,resistance to move-V ment is least at the lower position and greatest atthe upper position of said arm.

It is to be observed likewise that in the manner of threading the yarnthrough eyelets I, 2 and 3, two supporting strands of thread, that isone between eyelets I and 2 and the other between eyelets 2 and 3,operate to lift tension arm 4. At the lower position, the said twostrands are aP- the well known' manner, the braking circuit comprisingline 43, line 45, switch d1, line 69, line 46 and line 44. 48, line 45,switch 41, line 48, line 46 and line.43.

Power lines 43 and 44 are connected to the primary 5I of a powertransformer having secondaries 52, 53 and 54. Relay 55 is in series withsecondary 54 and plate 5B of tube 51. This ,tube includes grid58,cathode 69 and filament or heater B0.

Secondary 52 has line BI connectedl to the cathode 59 and filament B0.The latter is connected across secondary 52 by series connected lines 62and 63. Line 6I is extended at 64 and connected at 65 to a plurality ofparallel connected spindles 8. Juxtapositioned thereto are the springcontacts I2a and I2, each of the former connecting by a line -66 tosignal lamp 61 connected by line 68 to line 63j Thus each tension armherein has a signal light and same is indimachine.

vidual to that arm so the operator can readily locate the thread break;interference, etn, in the All contacts I2 are connected by line 59 totap 1b of resistor 1f-12,/ the latter being connected by line. tosecondary 53.- Tap 14 from sec; ondaries 53-54 connects at 15 to line6|. Line 16 from resistor 1I connects to grid 5B.

Now when any arm (spindle 8) engages spring I2 adjacent thereto (spindle8 having. upper and lower limit contacts 9 and Ill) the tube isenergized and relay liliy is energized to open switch 41 to the motorand close switch 41 to the brake, Thus immediately upon any arm 4attaining its upper or lower limit the motor is deenergized and thebrake applied and the individual warning signal- (as indicator-orlocator) is energized.

the effective rsultant effective- 'Ihe motor circuit comprises line Anaudible signal may be in multiple with each of thread failure andcxpedites machine reoperation.

While the invention has been illustrated and described in great detailin the drawing and foregoing description, the same is to be consideredas illustrative and not restrictive in character.

The several modifications described herein as well as others which willreadilyrsuggest themselves to persons skilled in this art, all areconsidered to be within the broad scope of the invention, referencebeing had to the appended claims.

The invention claimed is:` 1. A constant tension device suitable forknitting, coming and `like machines, having in combination a rockinglever with two arms, one of' 3 5. The structure as defined by claim 1wherein a switch is mounted with lrespect to said lever and `is operatedby movement thereof, a suitable source of electrical supply connected tothe switch, an electric motor, and braking means for machine operationand stoppage respectively and connected to said supply, meanscontrolling the latter connection, and means controlled by said switchfor actuating said last mentioned means for effecting motor stoppage,said first mentioned controlling means including a switch normallybiased to motor circuit position and movable by the lastmentioned meansto motor open'circuit and brake closed circuit position. y

6. The structure as defined by claim 1 wherein a switch is mounted withrespect to said lever and is operated by movement thereof, a suitablesource of electrical supply connected to the switch, an electric motor,and braking means for machine operation and stoppage respectivelyl andconnected to said supply, means controlling the latter connection, andmeans controlled by said switch for actuating said last mentioned meansfor effecting motor. stoppage, said iirst mentioned controlling meansincluding a switch normally biased to motor circuit position and movableby said arms being longer and having at its end an eyelet for guidingyarn and the other end of said arm being shorter and carrying acounterbalancing Weight adjustably-positioned thereon, the said entirelever system being pivoted to move freely in a vertical plane about a'point of equilibrium, means pivotally supporting said lever, the saidlong arm being adjustable to provide a change in the position of thecenter of gravity of the said lever system in a vertical plane includingthe sweep of said arm, the said center 'of gravity being lifted byupward movement of said lever and oiering constantly increasingresistance to said movement as the angle through which it has moved isincreased, a second eyelet positioned substantially in the plane ofmovement of said lever to guide yarn from a source of supply to the saidfirst eyelet on said long lever arm, and a third eyelet also positionedsubstantially in the plane of movement'of the lever machine, the saidthree eyelets being positioned with respect to each other so as toprovide friction on the yarn and thereby to provide a constantlyincreasing effective lifting force on the long arm of said lever.

2. A tension device as dened by claim 1 wherein there is providedresilient means engageable by the lever as the same'approaches its upperlimit of movement and for` progressively impeding further movementtoward said upper limit.

source of electrical supply connected to the switch, an electric motor,and braking means for machine operation and stoppage respectively andconnected to said supply, means controlling the latter connection, andmeans controlled by said .switch for actuating said last mentioned meansfor effecting motor stoppage and braking of the machine.

` to guide yarn from the said first, eyelet to the v the last mentionedmeans to motor open circuit and brake closed circuit position, said lastmen,

tioned means including a relay.

'7. The structure as dened by claim l wherein a' switch is mounted withrespect to said lever and is operated by movement thereof, a suitablesource 8. A constant tension devicecomprising three substantiallycoplanar thread guides, twoof the guides being comparatively close toeach other and the intermediate guide being simultaneously.

movable toward or away from the same, a pivotally supported,counterbalanced substantially horizontally directed arm for saidintermediate movable guide and beneath the other two guides, said armmoving substantially in the plane of `said guides, the directionandextent of the arm movement being proportional to the thread tension,

and resilient means operatively engageable by the arm in its guidemovement toward the other guides and progressively impeding such armmovement toward ysaid other guides.

'9. A tensin device as defined by claim 8 wherein there is providedacontrol switch, and

means vcarried by the arm for operative engager.y

ment with the switch when the arm is tilted closesttothe said otherguides. v

. '10. A tension device as dened by claim 8 wherein there is provided acontrol switch, and

means carried by the arm for operative engagement with the switch whenthe arm is released from thread tension.

dual, arcuately spaced means carried bythe arm for selective operativeengagement with the switch when the arm is tilted closest to said otherguides or when the arm is released from thread tension.

12. In a control system for knitting, coning and like machines having adriving motor and a brake, and switch means differentially controllingsame, the combination of a single means controlling said switch means, aplurality of yamtensioning devices, there being one for each yarn andhaving a portion movable proportional to the tension or lack of same,responsive switch means brake, and switch means diierentiallycontrolling same, the combination of a single means controlling saidsim'tch means, a plurality of yarn tensioning devices, there being onefor each yarn and having a portion movable proportional to the tensionor lack of same, responsive switch means for each device and actuable bysaid portion at the limits of portion movement, a warning signal foreach device and operable thereby and energizable by the second mentionedswitch means at either limitI of portion movement,and a singleA means inseries with all of said second mentioned switch means and operable byany one of same for actuatingsaid rst mentioned switch means, andarl-audible signal in multiple with the said single means andsimultaneously operable therewith.

14. In a control system for knitting, coning and like machines having adriving motor, and a brake, and switch means differentially controllingsame, the combination of a single `means controlling said: switch means,a. plurality of yarn tensioning devices, there being one for each yarnand having a portion movable proportional to the tension or lack ofsame, responsive switch'- f01' @lich device and actuable by Said mltifmat' means for each device and actuable by said portion at the limits ofportion movement, a warning signal for each device and operable therebyand energizable by the second mentioned switch means at either limit of-portion movement, and a single means in series l withy all of said'second mentioned switch means and operable by any one of same foractuating said irst mentioned switch means, said single means comprisingan electronic relay and an electronic tube.

15. In a controlsystem for'knitting, coning and v said single meanscomprising an electronic relay and an electronic tube, and anaudible-signal in like machines having a driving. motor and a brake, andswitch means differentially controlling switch means and operableby anyone of same for actuating said rst mentioned switch means,

multiple with the said single means and simultaneously operabletherewith. .i

16. In a control system for knitting, coning and like machines having adriving motor and a brake, and switch means diierentially controllingsame, the combination of a single means controlling said switch means, aplurality of .yarn tensioning devices, there being one Afor each yarnand having a portion movable proportional to the tension or lack ofsame, responsive switch means for each device and actuable by saidportion at .the limits of portion movement, a Warning signal for eachdevice and operable thereby and. energizable by the second mentionedswitch means at either limit of portion movement, and a single means inseries with all of 'said second mentioned switch means and operable byany one of same for actuating said first mentioned switch means and avisual signal in multiple with said single IDBanS.

17. In a control system forknitting, coning and like machine having adriving motor and a 40 brake, andswitch means differentiallycontrolling- @s tension or-lack of same, responsive switch means saidsingle means comprising an electronic relay and an electronic tube.

y ROBERT N. AUBLE.

